Nebulizers produce aerosol by atomizing water, saline solutions, drug solutions for treating diseases in the respiratory system or the like, or liquids such as vaccines. A typical nebulizer includes a nebulizer kit that produces the aerosol. JP H6-285168A (Patent Literature 1) can be given as an example of a background art document disclosing a nebulizer kit.
A typical nebulizer kit 1000Z will be described hereinafter with reference to FIG. 60. FIG. 60 is a cross-sectional view illustrating the nebulizer kit 1000Z. The nebulizer kit 1000Z includes a case body 900, an atomizing area formation member 920, a flow channel formation member 930, and an atomizing area M.
Case Body 900
The case body 900 is formed as a closed-ended cylinder. An upper opening 902 is provided in an upper area of the case body 900. A compressed air introduction tube 913 and a liquid reservoir portion 916 are provided within the case body 900. The compressed air introduction tube 913 extends upward from a base of the case body 900 (that is, from the side on which the liquid reservoir portion 916 is located). Compressed air (not shown) is introduced into the compressed air introduction tube 913.
A nozzle hole 915 for ejecting the compressed air is provided in an upper tip area 913a of the compressed air introduction tube 913. The liquid reservoir portion 916, which serves to hold a liquid W, is provided so as to surround an outer circumferential surface of the compressed air introduction tube 913 on a lower end of the compressed air introduction tube 913.
Atomizing Area Formation Member 920
The atomizing area formation member 920 includes a liquid suction tube formation area 924, a baffle portion 922, and a baffle support portion 923. The liquid suction tube formation area 924 is formed as a cylinder. The diameter of the liquid suction tube formation area 924 decreases as the liquid suction tube formation area 924 progresses upward. An opening 924a is provided at the apex of the liquid suction tube formation area 924. The baffle portion 922 has a projection 925 located immediately above the opening 924a. The projection 925 is provided as necessary.
The baffle support portion 923 extends toward a side area of the baffle portion 922 from an outside surface of the liquid suction tube formation area 924. The baffle portion 922 and the projection 925 face the opening 924a with a gap provided therebetween. The atomizing area formation member 920 is contained and disposed within the case body 900 so that an outer surface of the compressed air introduction tube 913 is covered by the liquid suction tube formation area 924.
Flow Channel Formation Member 930
The flow channel formation member 930 is attached to the case body 900 so as to cap an upper opening 902 in the case body 900. The flow channel formation member 930 includes an aerosol discharge port 932 and an outside air introduction tube 934. The aerosol discharge port 932 is provided in an upper area of the flow channel formation member 930. Aerosol produced within the case body 900 (at the atomizing area M) is discharged to the exterior from the aerosol discharge port 932. The outside air introduction tube 934 is provided so as to pass through the flow channel formation member 930 from top to bottom. Outside air used to produce the aerosol is introduced through the outside air introduction tube 934, from the exterior of the case body 900 toward the interior of the case body 900 (the atomizing area M).
Atomizing Area M
FIG. 61 is a cross-sectional view illustrating the atomizing area M in the nebulizer kit 1000Z in an enlarged manner. The atomizing area M is formed between the baffle portion 922 (the projection 925) provided in the atomizing area formation member 920 and the nozzle hole 915 provided in the compressed air introduction tube 913 (see FIG. 60).
The compressed air introduced into the compressed air introduction tube 913 is expelled through the nozzle hole 915 provided in the upper tip area 913a (see an arrow AR913). After being expelled from the nozzle hole 915 toward the projection 925, the compressed air collides with the projection 925 and the baffle portion 922, changes direction, and spreads out radially (see an arrow AR922). A negative pressure, where the pressure is lower than the surroundings, is produced at the atomizing area M and the vicinity thereof.
The liquid W is sucked upward to the vicinity of the atomizing area M from the liquid reservoir portion 916 due to the negative pressure produced at the atomizing area M and the vicinity thereof (see an arrow AR915). The liquid W collides with the compressed air flowing in the direction of the arrow AR922 and breaks up as a result, changing into mist particles (fine droplets) (not shown).
These mist particles attach to the outside air introduced into the case body 900 through the outside air introduction tube 934 (see an arrow AR934). The aerosol is produced at the atomizing area M. The aerosol swirls (see an arrow AR932) toward the aerosol discharge port 932 (see FIG. 60) and is discharged to the exterior through the aerosol discharge port 932 (see FIG. 60).